Gametoy locomotion apparatus

ABSTRACT

Objects having different coefficients of friction may be propelled across a common playing surface by different modes of directional vibration under the control of opposing players. If the repetition rate of the vibrational modes are also made variable, the players may command both the speed and heading of their own objects. Such a locomotion apparatus has numerous applications as a competitive gametoy.

United States Patent [151 3,698,713

Jimerson 1 Oct. 17, 1972 [54] GAMETOY LOCOMOTION 3,463,495 8/1969Christensen ..273/86 E X APPARATUS 1,755,621 4/1930 Whitehouse ..273/86E [72] inventor: Bruce D. Jimerson, 1815 Vallecito Drive San Pedro, Cam,90732 Primary Exammer Anton O. Oechsle [22] Filed: June 18, 1970 [57]ABSTRACT 21 AWL 47,549 Objects having different coefficients of frictionmay be propelled across a common playing surface by different modes ofdirectional vibration under the con- U-S. E, C, A no] of opposingplayer5 the repetition rate of the [51] Int. Cl. vibrational modes arealso made variable the pl s [58] Field of Searc 94 may command both thespeed and heading of their 46/ 198/220 own objects. Such a locomotionapparatus has numerous applications as a competitive gametoy.

[56] References Cited UNITED STATES PATENTS 9 Claims, 28 Drawing Figures2,330,946 10/1943 Bergmann A 1: I w I l I) g I! 50 I r z w I I l 4] J iI j-ZZ J 25 i i I? 24 k45 PATENTEDIIBI 17 I972 3' 698,7 1 3 sum 2 or 6INVENTOR.

524/65 0. J/MEESOA/ I PATENTED I973 3.6 98 T l 3 saw a or 6 E65INVENTOR. 47 BEL/CE 0. #4454 50 minimum I972 3.698.713

snmums 10) Y 10/ L (/3 m L I "i I I I m m i G I .4, 6A.

i i i I m rs 5 1 l l (I i J54. 6'6,

I E L m m i I NVEN'T OR.

1 GAMETOY LOCOMOTION APPARATUS BACKGROUND OF THE INVENTION Reference toUS. Pat. application Ser. No. 810,207, filed Mar. 25, 1969, by Bruce D.Jimerson, the contents thereof being incorporated as backgroundinformation for the purpose of describing prior art locomotion systems.

In recent years the toy manufacturers have put increasing emphasis uponcreative toys and games which will promote reciprocal interplay betweenthe participants and the game pieces. For example, in successful actiontoys like the slot car sets, the speed control provides the means bywhich the operators transfer their response and emotions to become thedaredevil drivers of a miniature race track. In another action gametoydescribed in the above-referred to patent application, the playersmanuever their ships by remote control to battle one another on thesurface of an artificial ocean. Another type of action gametoy enjoyingprolonged commercial success is the vibrational football game in whichtwo different football teams may be lined up by opposing players and thefield vibrated so as to move the pieces in a more or less randomfashion. In these, and other action gametoys however, the entertainmentfactor depends to a great extent on the amount of control which theparticipating players enjoy. Thus, in the case of the slot car, theplayer can control speed but not direction. In the vibrational footballgame, after the pieces are initially lined up, their movements are moreor less random; neither team having any control over the motions of itspieces relative to the pieces of the opposing player. In the NavalAction Gametoy the players have separate control over their own ships,but only on a limited part of the playing board. Furthermore, as thedegree of control is increased, the cost of manufacture rises sharply.Thus, in the Naval Action Gametoy, four separate motors are required topropel two separate and independent X-Y drive systems. Since the cost ofmanufacturing a plaything is very important in determining itscommercial success. a desirable objective of any propelling apparatus ofa controllable gametoy is that it be inexpensive.

SUMMARY OF THE INVENTION In accordance with the background informationand prior art description, a paramount object of the present inventionis to provide a low cost controllable gametoy.

Another object of the present invention is to provide a competitivegametoy having a plurality of moving pieces, each of which may beremotely controlled as to velocity and direction.

A further object of the invention is to provide a competitive race cargame wherein each player may separately control the speed and velocityof his own vehicle.

It is another object of the invention to provide a competitive footballgametoy wherein each player may remotely control the motion of his ownteam.

It is another object of the present invention to provide a competitiveNaval Action Gametoy wherein each side may remotely control its ownfleet on a common playing surface.

It is another object of the present invention to provide a locomotionapparatus which may be used to produce the desired motions and controlfor any of the above referred to gametoy embodiments and which may alsobe applied to other devices having as a requirement an inexpensivemotion control for propelling a moving object relative to a horizontalsurface.

These, along with other objects and advantages of the invention to begleaned from the detailed description of a particular embodiment givenhereinbelow, are achieved by the use of a directional oscillatory plane.The plane (or playing surface area) is arranged so that it may be freelyvibrated in any direction parallel with the surface of the plane. Themovable objects are of different weights and have different coefficientsof friction so that some of the objects (those under the control of afirst player) are effected by only one mode of oscillation whereas otherobjects (those under the control of a second player) are effected onlyby a different mode of oscillation. As a consequence, each player mayseparately control his own team, ships, cars or whatever, to move in andabout, push around, or chase after the opponents forces. Since eachplayer has complete and full control of his own pieces over the entireplaying surface, there are numerous life-like actions which may besimulated on a small scale in a manner not heretofore possible.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a cutaway view showing the playingsurface and a portion of the propelling apparatus.

FIG. 2a is a cross-sectional view of the gameboard and drive apparatus.

FIG. 2b shows a throttle detail.

FIG. 3 shows an exploded view of the right side cam assembly.

FIG. 4a shows in detail the location of the cam detents.

FIG. 4b shows how the shape of the cam detents and slots enableregistration of the cam lobe opposite to the cam follower protrusion.

FIG. 4c shows a situation where the cam detent is displaced beyond thepoint where the V-shaped detent can effect registration.

FIG. 5 shows an alternative embodiment employing a push down rotatableknob for steering and throttle control.

FIGS. 6a-6d show pictorially the displacement of the playing surface andobject undergoing a vibratory acceleration cycle.

FIGS. 7a-7f show the acceleration, velocity and displacement profiles ofthe playing surface and object for one complete acceleration sequence.

FIGS. 8a-8e show the acceleration, velocity and displacement profile forthe playing surface and the displacement profiles for two objects havingdifferent coefficients of friction where the playing surface issubjected to a first vibration mode.

FIGS. 8f-8j show the same quantities where the playing surfaceissubjected to a second vibration mode.

DESCRIPTION OF A PREFERRED EMBODIMENT Adverting to the drawings, andparticularly to FIGS. 1 and 2a, a preferred embodiment of the inventioncomprises a smooth horizontal playing surface 10 which is supported fromunderneath by a substructure frame 11 having two transverse beams 12 and13 spaced about one-fourth of the distance from each end of the playingsurface, neither of which is attached to the playing surface the playingsurface 10 itself is elastically coupled to the substructure frame 11 bytension spring 14-19. Springs 14-17 have an elastic constant of 10 timesthat of the springs 18 and 19 so as to minimize the rotational motionwhich would result from applying off center forces to the playingsurface 10. Such an arrangement permits the playing surface 10 to betranslated in any direction (in an oscillatory fashion) relative to theframe 11 as described below. The frame 11 is preferably of a plasticconstruction and the playing surface may be either a thin sheet ofplastic or metal.

An oscillatory motion of the playing surface is brought about by therevolving cams 22 and 23. The cam 22 is driven by the gear 24 and cam 23is driven by gear 25. The gears 24 and 25 are located on diametricallyopposite sides of the lost motion drive gear 30 which is arranged tohave an odd number of sectors of teeth so that only one of the gears(either 24 or 25) may be driven at any one time. The lost motion drivegear 30 is actually comprised of three separate discs, the top disc Ahaving only three sectors of teeth (at iocations 31, 34 and 37) and themiddle disc only 6 sectors of teeth (at locations 31, 32, 34, 35, 37 and38) whereas the bottom disc C has teeth sectors at all of the ninelocations (31-39). All three sectors are preferrably made of nylon andare bonded together using any conventional means so as to form thecomposite gear 30. The motor 40 which drives the gear 30 at a constantspeed is preferrably an inexpensive 110 volt 60 cycle AC induction motorsimilar to the type used in inexpensive household items, although itwill be understood that any type of device capable of producing areasonably constant rotational speed may suffice for this purpose.

When the motor 40 is energized, the lost motion gear 30 is caused torotate at a constant speed. The playing surface 10 can then be moved inan oscillatory fashion by lowering either (or both) of the gears (24 or25) on its respective bearing post (41 or 42) until the teeth of thelost motion gear 30 are engaged. For example, assume that the throttlehandle 43 is moved downwardly in the direction of the arrow 45 so as tocompress the bottom portion of the compression spring 47. (This isaccomplished as shown in FIG. 2b by making the slotted opening 49 of thethrottle handle wide enough to accomodate the diameter of the bearingpost 41 but not lower compression spring 47.) When the bottom portion ofthe lower compression spring 47 is thus compressed, the uppercompression spring 50 functions to move the cam follower 26 (togetherwith the cam 22 and its attached gear 24) downwardly on the bearing post41. If the throttle lever 43 is depressed only part way so that the gearengages only the teeth of the A disc, only three oscillary cycles willbe transmitted to the playing surface for each revolution of the gear30. If however, the throttle 43 is depressed further, the gear 24 willmove to engage the teeth of both the A and B discs so that six oscillarycycles are transmitted for each revolution of gear 30. Similarly, withthe throttle fully depressed nine oscillatory cycles result. Since (aswill be explained below) each oscillatory cycle results in a fixedincrement of movement of the object under control, the velocity ofpropogation of the controlled object will be directly dependent upon thevertical location of the gear 24 with respect to the lost motion gear30. The member 43 is thus properly termed a throttle lever in that itmay be varied to increase or decrease object velocity.

In order to understand the arrangement for controlling the direction,reference may be had to the exploded view of the cam assembly shown inFIG. 3. When the gear 24 (and its intergally attached cam 22) is loweredon the bearing post 41, the teeth of the lost motion gear intermittentlyengage the teeth of the gear 24 causing the cam to make one completerevolution for each engaged sector of teeth on the lost motion gear 30.The rotatable cam follower 26 will experience one cycle of translatorymovement for each rotation of the cam 22. The direction of thistranslational vibration will depend upon the position of the camfollower protrusion 62. As the cam follower 26 is rotated via thesteering wheel 63, the position of the cam follower protrusion 62changes so that the direction of vibration also changes. The camfollower 26 is arranged so that it may continuously rotate within thecylindrical shell 64, the latter being rigidly attached to the undersideof the playing surface 10. The outside diameter d of the bottom part ofthe cam follower 26 is made slightly smaller than the inside diameter di of cylindrical shell 64 (slip fit). This allows the cam follower 26 tobe rotated with respect to the cylinder 64 (to change the vibrationdirection) or to slide axially with respect to the cylinder 64 when thethrottle 43 is moved to vary the velocity. The translational motion ofthe cam follower 26 is transmitted to the wall of the cylindrical shell64 which in turn vibrates the playing surface 10.

The compression springs 50 and 47 cause the cam 22 and cam follower 26to remain together (with the cam 22 inside of the cam follower cavityirrespective of the throttle position. Thus, as the throttle arm 43 islowered, the spring 50 drives both the cam 22 and cam follower 26downwardly on the bearing post 41. When the throttle arm is raised, thecam 22 and cam follower move up together. The length L" of the camfollower is made such that the cam gear 24 just clears the top of thelost motion gear 30 when the top turret part 65 of the cam followercontacts the underside of the playing surface 10, provided that the cam22 and cam follower 26 are rotationally aligned so that the detentflanges 66 and 77 on top of the cam are juxtaposed to the detent slots68 and 69 on the inner end of the cam follower cavity 70. This assuresthat the cam lobe 61 is properly registered with respect to the camfollower protrusion 62 for the next rotational cycle.

The importance of registering the cam lobe 61 relative to the followerprotrusion 62 lies in the dynamics of the locomotion principle to beexplained below. At this point it will be sufficient to say that the camlobe 61 must come to rest exactly opposite the follower protrusion 62.If, for example, there were no detent arrangement and the throttle werelifted upwardly at a time when the cam gear 24 was being driven by thelost motion gear 30, the teeth of the gear 24 might disengage the teethof gear 30 leaving the cam lobe 61 at any arbitrary position withrespect to the protrusion 62. Because of the detents however, gear 24will not clear the teeth on the upper disc A of gear 30 until the camlobe 61 is opposite the protrusion 62 so that the detents 66 and 67occupy the detent slots 68 and 69 respectively. As shown in FIG. 4a, thedetents (as well as the detent slots) are located at slightly differentradial distances so that there is only one mating position. Thus, withthe throttle lever 43 in the up position, the teeth of disc A willcontinue to drive the cam gear until it is rotated to a point where thedetents 66 and 67 register with the slots 68 and 69, at which point thespring 47 functions to raise the cam gear beyond the influence of thegear 30; the relationship between the cam lobe 61 and the cam followerprotrusion 62 being preserved irrespective of the angular position ofthe protrusion 62. It will be noted that the detents are V- shaped so asto facilitate catching the slots even though the cam lobe 61 is notexactly opposite the protrusion 62. This permits directional change tobe made via the steering wheel while the cam is being intermittentlydrive by the toothed sectors of gear 30. Since the angular rotation ofthe steering wheel 63 will normally be much less than the angular speedof the cam, the slight error resulting from the angular displacement ofthe cam follower due to steering while the cam gear 24 is engaged by thegear 30 may be compensated for by the V-shaped detents. Thus, as shownin FIG. 4b, even though the detent 67 is not perfectly positioned withrespect to the complementary slot 69, the spring forces on the twomembers cause the detent 67 to slide along the ramp 90 of the slot 69until complete accordance is reached. If, however, due to somepeculiarity the detent 67 is too far out of position (as shown in FIG.4c) when the cam gear 24'cornes to rest after an oscillation cycle, thethrottle handle 43 may be raised all the way to allow disc A to drivethe cam gear to registration as described above.

Rotation of the cam follower to effect directional changes isaccomplished by turning the wheel 63 in the desired direction. The wheel63 is attached to the hollow steering shaft 72 by a pin 73 throughaccordant holes 74 and 75 in the wheel hub 76 and steering shaft 72respectively. The inner diameter d of the hollow shaft 72 is madeslightly larger than the diameter of the bearing post 41 (to provide aslip fit). The wings 77 and 78 on the steering shaft 72 function toengage the slots 79 and 80 on the guide turret 65 of the cam follower26. In order to avoid impairing the free transfer of energy from the cam22 to the playing surface 10, it is important to isolate both theplaying surface and cam follower from any contact which would bedetrimental. For this reason, the inside diameter of the turret 65 ismade approximately 3/16 of an inch larger than the outside diameter (1:,of the steering shaft 72. Similarly, the slots 79 and 80 are made bothwider and deeper than the corresponding dimensions of the wings 77 and78. The width over size should not, however, be large enough to producea noticeable play or loseness in the steering characteristics of theapparatus.

The steering wheel 63 may be rotated to change the oscillatoryorientation at any time, whether or not the cam gear 24 is being drivenby the lost motion gear 30. As was explained above, the speed at whichthe steering changes are made is usually much less than the angularvelocity at which the cam is rotated by the gear 30. Hence, under normaloperating conditions, registration between the cam 24 and cam follower26 will be established by the complimentary V-shaped slots and detentseven if the cam follower 26 is angularly displaced a small amount duringa rotation of the cam. As shown in FIGS. 2a and 3, the pin 73 serves thedual function of connecting the hub 76 of the steering wheel 63 to thesteering shaft 72, and in addition, it prevents the steering wheel frombeing depressed by virtue of its contact with the top of the bearingpost 41. For race car and boat manuvering games and the like, thesteering wheel 63 throttle lever 43 combination is idea]. If the playingsurface is used to propel objects which are not normally steered with awheel (e. g. miniature football players) it may be desirable to use adifferent control motif such as a rotatable push down knob which willfunction to vary both speed and direction. The present embodiment may beeasily adapted to this end by unscrewing the throttle handle 43 andreplacing the steering wheel 63 with the spring loaded knob 96 shown inFIG. 5. The inner wall 94 of the knob shaft is adapted to have a smallgroove 98 which accomodates the flange 95 on the steering shaft 72. Theknob 96 may thus be rotated to effect direction changes or pushed downto increase velocity, the inner spring 99 functioning to depress thesteering shaft and cam follower in proportion to the downward forceapplied.

It will be understood that the explanation of the right side camassembly is equally applicable to the left side cam assembly (i.e. parts23, 25, etc.). The only difference between the two assemblies lies inthe shape of the cams themselves. In order to understand the reason forthis difference and how it can be used to produce a separate andindependent control of different objects on the same playing surface, itis necessary to consider the dynamics of the locomotion principle whichlies at the root of the invention.

Referring now to FIG. 6a, the locomotion principle may be understood byconsidering the effect of a translational displacement of the playingsurface 10 relative to a movable object 100. If the coefficient offrinction between the playing surface 10 and object 100 is u then themaximum horizontal force which the playing surface can exert on theobject is where M is the mass of the object and g is the gravitationalacceleration, namely 32ft/sec Since force is equal to mass timesacceleration, the maximum horizontal acceleration of the object 100 (dueto movement of the playing surface 10) is Max Acceleration F max/MHence, no matter how fast the playing surface 10 is moved, the objectacceleration is limited to n times the gravitational acceleration. Thus,for a friction coefficient u 0.5, the object 100 will move with theplaying surface 10 when the playing surface 10 is accelerated below0.5g. When the playing surface 10 is subjected to horizontalaccelerations greater than 0.5g, the object 100 will slide with respectto the playing surface 10. When the playing surface is first subjectedto a horizontal acceleration less than 0.5g in one direction, and thenbrought back to its original position by an acceleration greater than0.5g, the final position of the object 100 is a displacement relative tothe playing surface. For example, assume that the playing surface 10 issubjected to an acceleration of 0.5g in the direction of the arrow 101and then brought to a stop by a 1.0g acceleration in the direction ofthe arrow 102. FIGS. 6b and 60 show pictorially what happens to both theobject 100 and the playing surface displacements. In FIG. 6b (during the0.5g acceleration) the object 100 moves the same distance forward (indirection of the arrow 10]) as the playing surface 10. When the 1gacceleration in the opposite direction is applied, the object 100 (whosevelocity is the same as that of the playing surface 10) cannot slow downas fast as the playing surface 10. Hence the object 100 slides withrespect to the playing surface 10 so that when both the object 100 andthe playing surface 10 come to rest, the object 100 is displaced withrespect to its initial position on the playing surface. If the playingsurface is then returned to its initial location in a manner which doesnot result in accelerations which would cause the object 100 to slide onplaying surface 10, the complete sequence will result in the object 100being displaced on the playing surface 10 a distance X I 1 as shown inFIG. 6d.

In a preferred embodiment-of the invention, the duration of the variousmovements of the playing surface l would be adjusted so as to return theplaying surface to its initial position with zero velocity, but with theobject 100 displaced. The sequence can then be repeated to produce afurther displacement of the object 100 and so on, with the averagevelocity of the object being dependent upon the number of vibrationsequences per unit time. For example, if each sequence caused the object100 to slide 1/10 of an inch, and there were 10 sequences per second,the average velocity of the object 100 relative to the playing surface10 would be 1 inch per second.

FIG. 7a shows a plot of an acceleration sequence which may be used tovibrate the playing surface 10 so as to return it to its initialposition with zero velocity. Assuming again that p. 0.5 so that theobject 100 does not slip with respect to the playing surface during theinitial acceleration of 0.5g, both the playing surface 10 and object 100will acquire a velocity of:

7 111 a dt 0.5 32 ti /i4 8 121m/n 4 10- sec) 7.7 in/sec as shown in FIG.7b. During the second part of the sequence (from 70 5 t 5 110) theplaying surface will acquire a velocity v due to the negativeacceleration a,, the value of which is:

110 v =7.7 in./see.f a dt Finally, during the period 110 t S 150, afinal velocity v results:

In FIG. 7c, the displacement of the playing surface is shown as afunction of time. Thus, at time t 70, the playing surface will havemoved from its initial position a distance:

= (0.5) (32 ftlsec (4 l0' sec) 12 in/ft =0.l53 inches at time t= 110,the playing surface will have moved to the point (0.5) (32 ft/sec (4x10sec) 12 in/ft 0.153 in (2X10 ft/sec) (4X10 sec) l2 in/ft =0.l53 inchesand, at time 1 =1 50, the playing surface will have come to rest at thepoint S3 S2 +1/2dyt Ngt =O.l53 in+0.l53 0.306in 0 FIGS. 7d, 7e and 7fshow the acceleration, velocity and displacement of the object for thesame time intervals. Thus, during a time 30 E t S the object 100 doesnot slip with respect to the playing surface. Hence, at t= 70, theobject 100 will have travelled the same distance as the playing surface10 so that X 0.153 inches. During the time 70 E t 5 110, the inertia ofthe object causes it to continue moving even though the playing surfaceis brought to a stop (at t The force acting on the object is uM, so thenegative acceleration is F/M ,umg/m. Since this is the same as theacceleration a,, the object will simply slide forward a distance equalto that travelled during the time 30 S t S 70. Hence, during the time 705 t 5 I10, the object 100 moves to the point X for a total displacementof 0.306 in. Finally, during the time 1 l0 5 t S 150, the object movesbackwards as a consequence of the negative velocity of the playingsurface 10 during this time interval. However, since the velocity of theplaying surface 10 is increasing from the time t 1 l0 to t= 150, thereis a cross-over point P (at F) where the object 100 catches up to thevelocity of the playing surface. From this point on, the playing surface10 exerts a force on the object 100 which tends to increase its velocityas shown in FIG. 7e. When the playing surface comes to rest at t theobject will wind-up with a resultant displacement X which may becalculated as follows:

= 0.306 (16 ft/sec (20 X 10 sec) 0.23 inches It will thus be observedthat for the type of acceleration waveform shown in FIG. 7a, theresulting displacement X of the object 100 relative to the playingsurface is equal to the magnitude S of the board vibration.

It will be understood of course, that the numerical example given is byway of illustration only. If such a sequence of acceleration intervalswere actually employed, the maximum velocity obtainable can be estimatedby multiplying the maximum number of vibratory sequences per secondtimes the average resultant displacement per vibratory sequence. Thus,in this example, each sequence consumes 120 millisec. Hence, the maximumvelocity is 1000 millisec.

= 1.92 inches/sec.

sec.

In most gametoy applications, scale velocities on the i order of 0.3 to0.8 inches/second are entirely adequate. In these cases it is desirableto use a shorter vibration cycle duration in order to decrease themagnitude of 3/2 (32 ft/sec") (2 X sec l2 i ft) =0.l 14 inches I FIGS.8a 8] illustrate how the above principles apply to the gametoylocomotion apparatus illustrated in FIGS. 1-5 so that opposing playersmay exercise independent control over different objects on the sameplaying surface. FIGS. 8b and 8c show the velocity and displacementprofile of the playing surface when subjected to the accelerationsequence shown in FIG. 8a and FIGS. 83 and 8h show the velocity anddisplacement profile when the playing surface is subjected to theacceleration sequence shown in FIG. 8f.

Referring now to the acceleration sequence of FIG. 8a, the correspondingdisplacement of an object (No. l) on the playing surface having acoefficient of friction p. a g is shown in FIG. 8d and FIG. 8e shows thecorresponding displacement of a second object (No. 2) having acoefficient of friction 4a,,,,,. Object No.1 thus behaves in a manneridentical to that shown in FIG. 7f, moving with the playing surfaceduring that part of the cycle where the frictional force pMg is equal tothe inertial force Ma and slipping with respect to the playing surfacewhen the latter is subjected to acceleration components which exceed thefrictional forces. Object No. 2, having a frictional force greater thanthe maximum inertial force to which the playing surface is subjectedduring the cycle shown in FIG. 8a, does not slide with respect to theplaying surface. Hence, the displacement curve (FIG. 8e) of the object0,, is identical to the displacement curve of the playing surface (FIG.80). When the playing surface comes to rest at the end of the vibrationcycle, the object 0,, is exactly where it was at the beginning of thecycle. Hence, the acceleration sequence shown in FIG. 8a will effectonly the object No.1 and not the object No.2.

Consider next what happens to each object when the playing surface issubjected to the acceleration sequence shown in FIG. 8f. Object No. 2,having a frictional force equal to 4a moves with the playing surfaceduring the first part of the vibrating cycle, and then slips when theplaying surface is subjected to greater acceleration. The profile shownin FIG. 8j is therefore identical with that shown in FIG. 7f except thatthe time scale is compressed. The Object No.2 is thus displaced by thevibrating cycle shown in FIG. 8f but not by the vibrating cycle shown inFIG. 8a.

FIG. 8i shows the spurious displacement of Object No.1 as a consequenceof the acceleration cycle shown in FIG. 8]". Since Object No.1 slipsduring the entire acceleration sequence of FIG. 8f, and since theduration of the vibrating cycle is only a that shown in FIG. 8a, theresultant cross coupling error E is relatively small (about percent inthe case illustrated). This slight infiuence of the acceleration cycleshown in FIG. 8f can be easily compensated for by the contestants, or itcan be reduced even further by slightly modifying the accelerationprofile shown in FIG. 8f. Even if no compensation is employed, it willbe evident that for the practical purposes of a gametoy, the slightcross coupling error can be ignored and in essence, the accelerationprofile shown in FIG. 8a will motivate only Object No.1 and theacceleration profile shown in FIG. 8f will motivate only Object No.2.Hence, if the direction of the acceleration components shown in thesequences of FIG. 8a and the repetition rate of such sequences are underthe control of one player, and the direction of the accelerationcomponents shown in the sequence of FIG. 8f and its repetition rate areunder the control of a second player, the first player will be able tocommand the speed and direction of objects having one coefficient offriction and the second player will be able to command objects having adifferent coefficient of friction, so long as the two sequences do notoccur simultaneously.

Referring once again to FIGS. 1 and 2a, it will be seen that the camgears 24 and 25 are positioned opposite one another, and the lost motiongear 30 is arranged to have an odd number of toothed sectors. Thisarrangement assures that the playing board 10 is time shared so thatvibratory cycles do not occur at the same time. Thus, if both playershave their throttles fully depressed, there will be 18 cycles for eachrevolution of the lost motion gear 30. Nine of these will effect objectswith one frictional coefficient and nine will effect objects with adifferent frictional coefficient. If the time duration of the longestcycle is 60 milliseconds and the vibrating amplitude is 0.1 inches, themaximum velocity of an object under the command of either player is H2)(1000 millisec/60 millisec) (0.1 inch) 0.83 inches/sec In the examplegiven above (with both players operating under full throttle), theplaying surface is equally time shared. When one of the players reducesspeed by lifting the throttle, one of the cams will not be engaged ninetimes for each revolution of gear 30. There may thus be more of theshort duration cycles or more of the long duration cycles, dependingupon which player is commanding a higher velocity.

In order to generate the acceleration profiles shown in FIGS. 8a and 8f,the earns 22 and 23 must be shaped so that, when driven at constantangular velocity by the gear 30, the resultant displacement of theplaying surface (as of function of time) will be as shown in FIGS. and8h respectively. It will be evident that for a constant linear velocity,the displacement shown in FIGS. 80 and 8h will result from a cam lobehaving exactly the same shape. Thus, for a constant angular velocity,the cams 22 and 23 will have radial displacements equal to thecorresponding linear displacements shown in FIGS. 8c and 8h.

The importance of registering the cam lobe with the follower protrusioncan now be appreciated. If the acceleration sequence were to start atsome arbitrary point (e.g. t= 50 in FIG. 7a) the resultant displacementof the object X would be completely unpredictable. The detents 66 and 67together with the slots 68 and 69 thus assure that the cam lobe 61begins and ends opposite the protrusion 62. When the cam gear 24 isengaged by a sector of teeth on gear 30, it is thus turned one completerotation, the protrusion 62 being displaced in accordance with theprofile shown in FIG. 7c as the cam lobe 61 rotates. Since the outsideof the cam follower 26 is in contact with the cylinder 64, theprotrusion displacement is transferred to the playing surface.

Where higher translation velocities are desired, the object may bedesigned to have directional frictional characteristics which allow themto slip freely in one direction with respect to the playing surface, butnot in another. in most applications, and even those involving miniaturecars, locomotion velocities in the range of l inch/second are adequate.Since the cars are not in slots, but are steered around curves andobstacles, control becomes difficult at greater speeds. Where theapparatus is used to propel football players it is advantageous to makethe objects having a low coefficient of friction heavier than theobjects having a high coefficient of friction in order to balance theblocking characteristics of each team.

Different coefficients of friction are easily obtained by making thecontact base of the objects from different materials (e.g. plastic andrubber). It will be understood also, that the basic concept of theapparatus may be extended to more than two different types of objects.Thus, three different cams could be used having progressivly shorteracceleration sequence durations. This would be desirable, for example,in' controlling the ball carrier separately from the other members ofthe team or to control three separate miniature cars, etc. Thus,although a preferred embodiment of the present invention has been shownand illustrated, it will be understood that the invention is not limitedthereto, and that numerous changes, modifications and substitutions maybe made without departing from the spirit of the invention.

lclaim:

l. A locomotion apparatus comprising:

a horizontal playing surface;

vibration producing means for steering slidable objects on saidhorizontal playing surface comprising means for oscillating the entireplaying surface in a single direction parallel to the plane of saidplaying surface; and

means for controlling the azimuth direction of the oscillation of saidplaying surface without changing the azimuth orientation of the playingsurface.

2. The locomotion apparatus recited in claim 1 wherein said vibrationproducing means comprises:

means for producing an acceleration in one direction and a subsequentacceleration of a different magnitude in the opposite direction; and

means for controlling the duration of each of the accelerations to bringsaid playing surface to rest after said playing surface has beenaccelerated at least once in each direction.

3. The apparatus recited in claim 1. wherein said vibration producingmeans comprises:

means for cyclically applying a first magnitude aeceleration to saidplaying surface in one direction followed by a second magnitudeacceleration to said playing surface in a direction opposite todirection of the first acceleration;

means for controlling the number of vibratory cycles per unit of timewhereby the average velocity of slidable objects resting upon saidplaying surface may be varied.

4. The apparatus recited in claim 1 wherein said vibration producingmeans comprises:

a first vibrating means for displacing and returning said playingsurface so that objects having a first coefficient of friction which areresting on said playing surface will be displaced relative to saidplaying surface by said first vibrating means, but

not objects having a second coefficient of friction;

a second vibrating means for displacing and returning said playingsurface so that objects having a first coefficient of friction will notbe materially affected by said second vibrating means whereas objectshaving a second coefficient of friction which are resting on saidplaying surface will be displaced by said second vibrating means;

means for time sharing said first and second vibrating means so as toprevent the vibrations from occuring simultaneously.

5. The apparatus recited in claim 4 wherein is included:

means for independently controlling the repetition rate and direction ofsaid first and second vibrating means whereby both the velocity anddirection of objects having different coefficients of friction may beindependently varied.

6. The apparatus recited in claim 5 wherein said vibration producingmeans comprises:

a motor;

a lost motion gear driven by said motor, said lost motion gear having anodd number of toothed sectors;

diametrically opposed cam gears arranged to be moved to engage thesectors of said lost motion gear;

a first cam attached to one cam gear;

a second cam attached to the other cam gear, said first and second camsto be shaped to produce different acceleration cycles;

a cam follower in contact with each cam and in contact with said playingsurface whereby said playing surface can be vibrated by both cams whensaid motor is energized.

7. The apparatus recited in claim 6 wherein said lost motion gearcomprises a plurality of layers each having a different number oftoothed sectors; and

means for moving each of said cam gears independently to engage ordisengage the toothed sectors of difi'erent layers of said lost motiongear whereby the number of vibratory cycles per unit time produced byeach of said cams may be varied to effect independent velocity controlof objects having different coefficients of friction.

8. The apparatus recited in claim 6 wherein is included a means forindependently rotating each of said cam followers relative to theirrespective cams to change the direction of vibration of said playingsurface whereby the direction of travel of objects having differentcoefficients of friction may be independently controlled.

9. The apparatus recited in claim 6 wherein said lost motion gearcomprises a plurality of layers each having a different number oftoothed sectors;

means for moving each of said cam gears independently to engage ordisengage the toothed sectors of different layers of said lost motiongear whereby the number of vibratory cycles produced in a given time byeach cam may be varied to effect independent velocity control of objectshaving different coefficients of friction; and

1. A locomotion apparatus comprising: a horizontal playing surface;vibration producing means for steering slidable objects on saidhorizontal playing surface comprising means for oscillating the entireplaying surface in a single direction parallel to the plane of saidplaying surface; and means for controlling the azimuth direction of theoscillation of said playing surface without changing the azimuthorientation of the playing surface.
 2. The locomotion apparatus recitedin claim 1 wherein said vibration producing means comprises: means forproducing an acceleration in one direction and a subsequent accelerationof a different magnitude in the opposite direction; and means forcontrolling the duration of each of the accelerations to bring saidplaying surface to rest after said playing surface has been acceleratedat least once in each direction.
 3. The apparatus recited in claim 1wherein said vibration producing means comprises: means for cyclicallyapplying a first magnitude acceleration to said playing surface in onedirection followed by a second magnitude acceleration to said playingsurface in a direction opposite to direction of the first acceleration;means for controlling the number of vibratory cycles per unit of timewhereby the average velocity of slidable objects resting upon saidplaying surface may be varied.
 4. The apparatus recited in claim 1wherein said vibration producing means comprises: a first vibratingmeans for displacing and returning said playing surface so that objectshaving a first coefficient of friction which are resting on said playingsurface will be displaced relative to said playing surface by said firstvibrating means, but not objects having a second coefficient offriction; a second vibrating means for displacing and returning saidplaying surface so that objects having a first coefficient of frictionwill not be materially affected by said second vibrating means whereasobjects having a second coefficient of friction which are resting onsaid playing surface will be displaced by said second vibrating means;means for time sharing said first and second vibrating means so as toprevent the vibrations from occuring simultaneously.
 5. The apparatusrecited in claim 4 wherein is included: means for independentlycontrolling the repetition rate and direction of said first and secondvibrating means whereby both the velocity and direction of objectshaving different coefficients of friction may be independently varied.6. The apparatus recited in claim 5 wherein said vibration producingmeAns comprises: a motor; a lost motion gear driven by said motor, saidlost motion gear having an odd number of toothed sectors; diametericallyopposed cam gears arranged to be moved to engage the sectors of saidlost motion gear; a first cam attached to one cam gear; a second camattached to the other cam gear, said first and second cams to be shapedto produce different acceleration cycles; a cam follower in contact witheach cam and in contact with said playing surface whereby said playingsurface can be vibrated by both cams when said motor is energized. 7.The apparatus recited in claim 6 wherein said lost motion gear comprisesa plurality of layers each having a different number of toothed sectors;and means for moving each of said cam gears independently to engage ordisengage the toothed sectors of different layers of said lost motiongear whereby the number of vibratory cycles per unit time produced byeach of said cams may be varied to effect independent velocity controlof objects having different coefficients of friction.
 8. The apparatusrecited in claim 6 wherein is included a means for independentlyrotating each of said cam followers relative to their respective cams tochange the direction of vibration of said playing surface whereby thedirection of travel of objects having different coefficients of frictionmay be independently controlled.
 9. The apparatus recited in claim 6wherein said lost motion gear comprises a plurality of layers eachhaving a different number of toothed sectors; means for moving each ofsaid cam gears independently to engage or disengage the toothed sectorsof different layers of said lost motion gear whereby the number ofvibratory cycles produced in a given time by each cam may be varied toeffect independent velocity control of objects having differentcoefficients of friction; and means for independently rotating each ofsaid cam followers relative to their respective cam to change thedirection of vibration of said playing surface whereby the direction oftravel of objects having different coefficients of friction may also beindependently controlled.